NYC Horticulturist
Comprehensive Resource To Help You Ace 2026-2027
Exams Includes Frequently Tested Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
Instant Download Pdf
1
What does pH stand for?
A. Plant hormones
B. Potential hydrogen
C. Phosphorus hydrogen
D. Percent humus
pH stands for 'potential hydrogen' — it measures the concentration of hydrogen
ions in a solution, indicating acidity or alkalinity on a scale of 0–14. Low pH = high
hydrogen ion concentration = acidic; high pH = low hydrogen ion concentration =
alkaline.
2
What pH value is considered neutral?
A. 5.0
B. 6.0
C. 7.0
D. 8.0
,A pH of 7.0 is considered perfectly neutral — neither acidic nor alkaline. Values
below 7.0 are acidic; values above 7.0 are alkaline (basic). Pure water has a pH of
7.0.
3
What pH range do most ornamental plants prefer?
A. 4.0–5.5
B. 5.5–6.5
C. 6.0–7.0
D. 7.5–8.5
Most ornamental landscape plants prefer a slightly acidic to neutral soil pH in the
range of 6.0–7.0. Within this range, most essential nutrients are readily available
for plant uptake. Outside this range, nutrients may become 'locked up' even if
present in the soil.
4
A soil with a pH of 5.0 is how many times more acidic than a soil with a pH of 7.0?
A. 10 times
B. 50 times
C. 100 times
D. 1,000 times
The pH scale is logarithmic — each unit represents a 10-fold change in acidity. A
pH of 5.0 vs 7.0 is a difference of 2 units, so it is 10 × 10 = 100 times more acidic.
This logarithmic relationship is why small pH changes require significant soil
amendments.
,5
A soil with a pH of 5.0 is how many times more acidic than a soil with a pH of 6.0?
A. 2 times
B. 5 times
C. 10 times
D. 100 times
One unit on the pH scale represents a 10-fold change. A pH of 5.0 is exactly 1 unit
lower than 6.0 — therefore it is 10 times more acidic. This is why precise soil pH
management matters: going from 6.0 to 5.0 dramatically changes nutrient
availability.
6
Which amendment is applied to LOWER soil pH (make it more acidic)?
A. Agricultural (Ag) limestone
B. Wood ash
C. Sulfur
D. Bone meal
Elemental sulfur is applied to soil to LOWER pH (increase acidity). Soil bacteria
convert sulfur to sulfuric acid over time, lowering the pH. It is commonly used for
acid-loving plants like blueberries, azaleas, and rhododendrons where soil pH
needs to be reduced.
7
Which amendment is applied to RAISE soil pH (make it less acidic)?
A. Sulfur
, B. Agricultural (Ag) limestone
C. Ammonium sulfate fertilizer
D. Peat moss
Agricultural (Ag) limestone (calcium carbonate) is applied to RAISE soil pH — to
make acidic soil less acidic (more alkaline). The calcium carbonate neutralizes soil
acidity. Ground limestone is slower acting but longer lasting than other liming
materials.
8
Which two factors change soil pH most rapidly?
A. Sun exposure and wind
B. Organic matter and earthworm activity
C. Water and fertilizer
D. Mulch type and soil depth
Water and fertilizer change soil pH most rapidly. Irrigation water (especially if high
in minerals) and fertilizers (particularly nitrogen-containing fertilizers) directly
alter the chemical balance and hydrogen ion concentration of the soil —
producing quicker pH shifts than slower-acting amendments like limestone or
sulfur.
9
A traditional rule of thumb states what percentage of a landscape should be
evergreen, and what percentage should be deciduous?
A. 50% evergreen, 50% deciduous
B. 60% evergreen, 40% deciduous
C. 80% evergreen, 20% deciduous
Comprehensive Resource To Help You Ace 2026-2027
Exams Includes Frequently Tested Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!! Current Update!!
Instant Download Pdf
1
What does pH stand for?
A. Plant hormones
B. Potential hydrogen
C. Phosphorus hydrogen
D. Percent humus
pH stands for 'potential hydrogen' — it measures the concentration of hydrogen
ions in a solution, indicating acidity or alkalinity on a scale of 0–14. Low pH = high
hydrogen ion concentration = acidic; high pH = low hydrogen ion concentration =
alkaline.
2
What pH value is considered neutral?
A. 5.0
B. 6.0
C. 7.0
D. 8.0
,A pH of 7.0 is considered perfectly neutral — neither acidic nor alkaline. Values
below 7.0 are acidic; values above 7.0 are alkaline (basic). Pure water has a pH of
7.0.
3
What pH range do most ornamental plants prefer?
A. 4.0–5.5
B. 5.5–6.5
C. 6.0–7.0
D. 7.5–8.5
Most ornamental landscape plants prefer a slightly acidic to neutral soil pH in the
range of 6.0–7.0. Within this range, most essential nutrients are readily available
for plant uptake. Outside this range, nutrients may become 'locked up' even if
present in the soil.
4
A soil with a pH of 5.0 is how many times more acidic than a soil with a pH of 7.0?
A. 10 times
B. 50 times
C. 100 times
D. 1,000 times
The pH scale is logarithmic — each unit represents a 10-fold change in acidity. A
pH of 5.0 vs 7.0 is a difference of 2 units, so it is 10 × 10 = 100 times more acidic.
This logarithmic relationship is why small pH changes require significant soil
amendments.
,5
A soil with a pH of 5.0 is how many times more acidic than a soil with a pH of 6.0?
A. 2 times
B. 5 times
C. 10 times
D. 100 times
One unit on the pH scale represents a 10-fold change. A pH of 5.0 is exactly 1 unit
lower than 6.0 — therefore it is 10 times more acidic. This is why precise soil pH
management matters: going from 6.0 to 5.0 dramatically changes nutrient
availability.
6
Which amendment is applied to LOWER soil pH (make it more acidic)?
A. Agricultural (Ag) limestone
B. Wood ash
C. Sulfur
D. Bone meal
Elemental sulfur is applied to soil to LOWER pH (increase acidity). Soil bacteria
convert sulfur to sulfuric acid over time, lowering the pH. It is commonly used for
acid-loving plants like blueberries, azaleas, and rhododendrons where soil pH
needs to be reduced.
7
Which amendment is applied to RAISE soil pH (make it less acidic)?
A. Sulfur
, B. Agricultural (Ag) limestone
C. Ammonium sulfate fertilizer
D. Peat moss
Agricultural (Ag) limestone (calcium carbonate) is applied to RAISE soil pH — to
make acidic soil less acidic (more alkaline). The calcium carbonate neutralizes soil
acidity. Ground limestone is slower acting but longer lasting than other liming
materials.
8
Which two factors change soil pH most rapidly?
A. Sun exposure and wind
B. Organic matter and earthworm activity
C. Water and fertilizer
D. Mulch type and soil depth
Water and fertilizer change soil pH most rapidly. Irrigation water (especially if high
in minerals) and fertilizers (particularly nitrogen-containing fertilizers) directly
alter the chemical balance and hydrogen ion concentration of the soil —
producing quicker pH shifts than slower-acting amendments like limestone or
sulfur.
9
A traditional rule of thumb states what percentage of a landscape should be
evergreen, and what percentage should be deciduous?
A. 50% evergreen, 50% deciduous
B. 60% evergreen, 40% deciduous
C. 80% evergreen, 20% deciduous
